RADIOMETER FLEX ABL90, Справочное руководство

Страница: 245 / 346

ABL90 FLEX reference manual 8. Parameters
8-29
Eq. 26 [8]:
The ODC is determined as described in equations 46-47 in the section
Oxyhemoglobin Dissociation Curve further in this chapter.
pO
2
(x) is calculated by a numerical method, using:
Eq. Description See…
26.1 S = ODC(P,A,T) Eq. 47
26.2
 
2,i
1 MetHb COHb
O
1 COHb MetHb
S F F
s
F F
  

 
Eq. 46.12
26.3
 
2,i
2,i
P
O
COHb
1
O 1 COHb MetHb
p
F
s F F


  
Eq. 46.10
26.4
 
i 2,i
2,i
t tHb 1 COHb MetHb O
+0.0105 O
c F F s
p
     

26.5 A = a
26.6 T = 37 °C
When t
i
= ctO
2
– 2.3 mmol/L, then pO
2,i
= pO
2
(x), where ctO
2
is determined as
described in equation 27.
pO
2
(x) cannot be calculated on the basis of a default ctHb value.
pO
2
(x) can only be calculated if the measured sO
2
(a)  0.97.
The calculation requires entering the sample type as "Arterial" or "Capillary".
Eq. 27 [5]:
 
2 2 2 2
tO O O O 1 COHb MetHb tHb c p s F F c        
 O
2
is the concentrational solubility coefficient for O
2
in blood (here set to
0.0105 mmol/L/kPa at 37 °C [24].
ctO
2
cannot be calculated on the basis of a default ctHb value.
NOTICE: The formula is different from previous Radiometer analyzers. The
oxygen solubility coefficient is now changed from 0.00983 to 0.0105 to be in
accordance with NCCLS (CLSI)-approved guidelines [24].
The change corresponds to 0.00067 mmol/L/kPa.
Eq. 28 :
ctO
2
(a  v– ) = ctO
2
(a) – ctO
2
(v– )
where ctO
2
(a) and
ctO
2
(v– ) are calculated from equation 27 for arterial and mixed
venous blood, respectively. The calculation requires two measurements and input
of both pO
2
(v– ) and sO
2
(v– ).
Eq. 29 [7]:
 
2
tHb 1 COHb MetHb BO c F F    
BO
2
cannot be calculated on the basis of a default ctHb value.
pO
2
(x)
(or p
x
)
ctO
2
ctO
2
(a  v– )
BO
2